Genome-Wide Identification, Classification, Expression Analysis, and Screening of Drought and Heat Resistance-Related Candidates of the Gene Family in Wheat.

Plant respiratory burst oxidase homologs (Rbohs) are key enzymes that produce reactive oxygen species (ROS), which serve as signaling molecules regulating plant growth and stress responses. In this study, 39 genes (-) were identified. These genes were distributed unevenly among the wheat genome's fourteen chromosomes, with the exception of homoeologous group 2 and 7 and chromosomes 4A, as well as one unidentified linkage group (Un). TaRbohs were classified into ten distinct clades, each sharing similar motif compositions and gene structures. The promoter regions of s contained -elements related to hormones, growth and development, and stresses. Furthermore, five genes (, , , , and ) exhibited strong evolutionary conservation. Additionally, a Ka/Ks analysis confirmed that purifying selection was the predominant force driving the evolution of these genes. Expression profiling and qPCR results further indicated differential expression patterns of genes between heat and drought stresses. , , , , , and were significantly upregulated under multiple stress conditions, whereas was only elevated in response to drought stress. Collectively, our findings provide a systematic analysis of the wheat gene family and establish a theoretical framework for our future research on the role of genes in response to heat and drought stress.